•    Dandilion_042010_0165_1

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      Aperture, is a mechanized device within a lens that opens and closes to adjust the amount of light entering the camera body effecting the exposure. With ISO determining the sensitivity of the film or sensor, the combination of the aperture and the shutter speed determine the amount of the light being recorded of the subject. When you determine the proper combination of shutter speed and aperture for a correct exposure, then adjustments can be made to either for creativity, which in turn effects a change to the other setting to keep a proper exposure.

    The two images above are of the same subject. The top one taken with a wider aperture giving us a very small amount of depth-of-field (depth-of-focus). Also because of allowing more light in, our shutter speed was shorter. The bottom image was taken with a smaller aperture giving us much more depth-of-field for more of the subject in focus. With a smaller aperture, less light is allowed through the lens at any time requiring a longer shutter speed to keep a correct exposure.

    So changing of the aperture will in some way effect either the shutter speed or ISO setting because they are all connected by the Exposure Triangle. Play with changing the aperture with your camera on Aperture Priority mode and watch how the shutter speed is adjusted by the camera.